How To Set Up 2 Batteries?????

i was thinking...my lights are diming.... and i have 2 bateries anyway....... so im gonna hook 2 up im thinking ill use a acid battery for starting and my inside lights.....lights and all that and my Lightning audio deep cycle battery for my system..... I would judt run one but the wiers to my battery are wierd........... how would i do this... I was thinking of ruiing my 2 guage wire to the back like it is not and hooking it up to my alt on top of the connection thats already there then just using the same ground as my system sound ok?..... then i was gonna run another 2 guage wire to my distribution block................ were would i need fuses? would i need afuse going from the alt to the back battery or can i just put my circut breaker between my back battery and my amp?

i have 2 batts in my setup,
its setup like this: postive from main battery to your 2nd battery BUT you must install
a regulator in between them so both get charged, you can find them at sounddomain
for pretty cheap, its a regulator or a isolator i beleave isolator and then after installing that in between the 2 batterys you just ground out the 2nd battery,
if im wrong then someone correct me but im pretty positive thats how they installed it in my car

I can tell you how to do this, but it will not fix your dimming problem. If anything it will be a hindrance as your already strained alternator will have to charge two batteries instead of one. The only reason I would add another battery is to allow me to play the stereo louder when the ignition is off.

yes, adding a second battery would not help your problem. Your alternator would still be just as strained, if not more so, to put out the power that your car needs. If you doubled anything it should be your alt.

In the process of building an enclosure for 2 12" Magnum D2's... should be fun :thumbsup

my alt is 150a amps....... I called starcraft and they said to add a second battery.......... im running 500 watts so there shouldnt be any strain the alt isnt getting itsw full capacity... because 8 guage wire is going to battery im gonna hook the second battery straight to the alt....... Im thinking about getting the idle increased also...... i was running 2 amps for a while when i went 2 1 no change so i think im gonna drop it 2 1 ohm and oly run 1 sub at 1000 rms and see what happens i think my interior stuff is taking up to many volts so a second battery should help

Maybe you don't understand how the charging system of your car works. The alternator does not directly power your electrical system. The electrical system throughout your car (including the various electrical components of your car stereo) is powered by your battery. The alternator in turn, changes engine power to electrical power to keep your battery charged so that you can start your car again. The dimming that you are experiencing is the amps sucking power out of the battery and for whatever reason, the alternator can't keep up. This could be several things but most likely:

1) Alt. not putting out enough current (not in this case, as you have 150A alternator)
2) Old/Weak battery (I assume that the battery you have is in good condition)
3) Wiring not adequate to handle the additional current (probably your case)

Now, back to the issue at hand. Two batteries will NOT fix your dimming problem. It's simple- a battery is a load on a charging system(in this case, the alternator). Add another and it's twice the load. Add another and it's three times the load. If anything it could get worse by adding additional batteries.

Before you hook up two batteries, try upgrading your stock wiring. Start by upgrading the gauge sizes for the "magic three":

Bat to ground
Alt to bat
Alt to ground

More often than not, this will totally fix your dimming problem. The shear fact that the dimming did not stop even when you upgraded your alternator makes me believe that the stock wiring is not capable of handling this additional current. Try this and let us know what happens.

Just for reference, I am running approximately 500 or so watts on my stock alternator and an Optima redtop. My lights were dimming as well, so before I invested in anything else, I upgraded the magic three. Now no dimming whatsoever whether at 2000 RPMs or at 800.

yeh thats exactly what im thinking....... but have u ever seen the wires in a acura legend? ..... finding the groun om my alternator is hard enough i still cant find it........ pluse the battery has 3 wires going to it now that i think about it thers only a 10 mabe 12 gaugae wire charging battery........... but they go thru this black bow and a nother 8 guage wire goes to the ignition it anyboidy could tell me how to increse my ground on the alt it would be apreciated but its really really techniqual...... has anybody got there ground increased by a shop.... how much does it cost? o yeh another thing the wire goes thru the engin.... yeh the engin..... it it were a american car then it would be easy but its not.... niot to mention its a ls model so the alt prevides power to the engin computer to check the sensors..... Has anybodyhave a acura legend or a 1989 accord and done this?.... help would be greatyly apreicated

that is what mine looks like now see how small the power wire is? it smaller then it looks of course thats now my car but still.... and mine has 3 wires going to the battery if i can increses the groungd i would like u just tell me what guage i need and how i can ground the alt.... I think its grounged for 150 amps already and look at the alt see that plug?......... my idea before was to just put a regular 1 guage wire on top of the orginal wire and hook it up like the mp to the metal...... and increase the groung would this work?

ok Update I called Starcharge.......... like they said my car sint built for 150 amps so im gonn ahave to increses the wires so rpe you were right.......... ok so heres the deal I still have a inline fuse holder left he said i at least need a 150 amp fuse in the line.... I think ill get a 200 amp fuse.... so he said i could just run the wire from the srew bit to the postive and just put it on top of the original teh run a wire from the alt to the negitive side of the battery adn ill increase the original ground on the battery sound like a good idea?........ do u think i can increase my power by 3 times this way?

the alternator (DOES) power the car when its running, not the batt

if you need proof that the alt runs the car when its on, just disconnect the battery when the car is running and it will continue to run. the alternator works the car and charges the batt at the same time.
think of it this way, the battery is to the alternator as the capacitor is to the battery.

My suggestion... call some shops in town and see if any of them can upgrade your wires for you.. I really don't think you want to start slapping wires from the alt to the battery, etc. If you don't know what you are doing you could start a fire or kill yourself (yes, kill yourself.. your body can shut down on 1 amp, your battery puts out 400 or more when shorted). I'm sure you can find a shop that will upgrade your wires to 4 AWG (for 150amp you might want to go to 2 gauge) for relatively cheap..

Or, try adding extra wires from here to there and see what happens.. *hides behind something acid proof*

Originally posted by Geminidj2000 o.......k......... so u think the wire upgrade wont help?

It could help.. depends.. if the juice can't get from the alt to your system fast enough, bigger better wires could help.. Just because the battery isn't directly used when the car is on doesn't mean the wire from the alt to the battery (or where ever else it might go) doesn't need to be adequate.. I"m not sure about newer cars, but I believe on older cars the alt/charging system/circuit is only through the battery.. in that the juice from the alt gets to the car from the wire on the battery as the alt doesn't directly tie into anything else (doesn't mean the jucie isn't comming from the alt, just doing it via the battery wire).. *shrug*